Head portion of a toothbrush



FIG. 1 is a front view of a head portion of a toothbrush according to the new design;

FIG. 2 is a right side view thereof, the left side view being the same;

FIG. 3 is a rear view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a front perspective view thereof:

FIG. 7 is a rear perspective view thereof;

FIG. 8 is a close up side view of the head portion thereof;

FIG. 9 is a close up rear view of the head portion thereof; and,

FIG. 10 is a close up rear perspective view of the head portion thereof.

All broken lines shown in the drawings are for environmental purposes only and form no part of the claimed design. 

The ornamental design for a head portion of a toothbrush, as shown and described. 